Electrically-controlled programmable deformation miniature supercapacitor based on liquid crystal elastomer and preparation method and application of electrically-controlled programmable deformation miniature supercapacitor

Abstract

The invention discloses an electrically-controlled programmable deformation miniature supercapacitor based on a liquid crystal elastomer and a preparation method and application of the electrically-controlled programmable deformation miniature supercapacitor. The electrically-controlled programmable deformation miniature supercapacitor sequentially comprises a flexible liquid crystal elastomer substrate, an interdigital electrode and a quasi-solid electrolyte layer from bottom to top, and a heating circuit is arranged at the bottom of the flexible liquid crystal elastomer substrate. The stimulus response performance of the liquid crystal elastomer is combined with the excellent electrochemical performance of the micro supercapacitor, and compared with a traditional energy storage device of a fixed geometric structure, the device can rapidly and reversibly respond to deformation under low-voltage stimulation while maintaining high energy density, excellent rate capability and good cycle life.

Description

Technical Field

[0001] The present invention relates to the technical field of micro and flexible energy storage devices, and particularly to an electro - controllable programmable deformation micro - supercapacitor based on liquid crystal elastomer, its preparation method and application. Background Art

[0002] With the continuous development of electronic devices towards flexibility and miniaturization, the demand for high - performance micro - energy storage devices is becoming increasingly urgent. Micro - supercapacitors (MSCs) have become the key to promoting the application of next - generation renewable energy and realizing seamless integration of energy systems and micro - electronic devices due to their advantages such as small volume, high charge - discharge efficiency, and long cycle life. Among them, planar interdigitated MSCs have more potential in improving device flexibility and reducing volume compared with traditional sandwich - type MSCs, and can better integrate into micro - electronic systems.

[0003] Currently, common processes for preparing planar micro - electrodes, such as lithography, template - assisted method, and laser writing, usually face problems such as complex processes, high costs, and difficulty in achieving fine control of electrode structures, which limit their large - scale promotion and diverse design requirements. In contrast, 3D printing technology, especially direct ink writing (DIW), has gradually become an effective way to fabricate high - loading and complex - geometry micro - electrodes due to its advantages of high precision, customization, low cost, and diverse material selection. By preparing inks from active substances such as graphene oxide, carbon nanotubes, MXene, etc. and printing layer by layer, not only can MSCs with excellent volumetric capacitance and energy density be obtained, but also MSCs with excellent structural stability can be constructed on flexible substrates such as paper, polyethylene terephthalate, and polyimide.

[0004] However, with the increasingly complex application scenarios of energy storage devices, traditional fixed - form MSCs are difficult to cope with changing environments and cannot meet the requirements of wearable micro - electronics. If energy storage devices can actively deform and achieve adaptive adjustment under external stimuli such as temperature, light, and electrical signals, their scope of use will be greatly expanded. Liquid crystal elastomer (LCE) has gradually become a promising class of flexible materials because it can produce large - amplitude and reversible deformation and has good processability and programmability. In recent years, by using DIW technology, it is possible to easily achieve mesogenic orientation in LCE with complex geometric structures. By programming the molecular orientation modes in different regions, diverse driving behaviors of LCE can be realized, providing the possibility for designing LCE flexible robots and functional devices. Further embedding photothermal conversion or resistive heating elements in LCE can precisely control the local temperature rise distribution of LCE, and then achieve its programmable deformation. Therefore, if advanced 3D printing technology is used to prepare high - performance MSCs based on LCE, it is expected to achieve multifunctional integration of programmable deformation and energy storage, meeting the requirements of self - adaptability and flexible integration of energy storage devices in complex environments. Summary of the Invention

[0005] The object of the present invention is to provide an electro - controllable programmable deformation micro - supercapacitor based on liquid crystal elastomer and its preparation method, aiming at the problems in the prior art that the structure of micro - energy storage devices is fixed, the deformation is uncontrollable, and it is difficult to achieve programmable deformation.

[0006] Another object of the present invention is to provide the application of the electro - controllable programmable deformation micro - supercapacitor based on liquid crystal elastomer.

[0007] The technical solution adopted to achieve the object of the present invention is as follows:

[0008] An electro - controllable programmable deformation micro - supercapacitor based on liquid crystal elastomer, which sequentially includes a flexible liquid crystal elastomer substrate, interdigitated electrodes, and a quasi - solid electrolyte layer from bottom to top. A heating circuit is provided at the bottom of the flexible liquid crystal elastomer substrate.

[0009] In the above - mentioned technical solution, the electro - controllable programmable deformation micro - supercapacitor is encapsulated by a polyimide film.

[0010] On the other hand of the present invention, the preparation method of the electro - controllable programmable deformation micro - supercapacitor includes the following steps:

[0011] Step 1: Mix a monofunctional polymerizable liquid crystal monomer, a bifunctional polymerizable liquid crystal monomer, a chain extender, and a photo - initiator in a preset ratio to obtain a polymerizable liquid crystal precursor; print the liquid crystal precursor on a pre - selected substrate by a printing method; finally, perform an in - situ photopolymerization reaction using ultraviolet light, and then the liquid crystal elastomer can be peeled off from the substrate to obtain the flexible liquid crystal elastomer substrate.

[0012] Step 2: Uniformly mix MXene nanosheets, an aqueous solution of conductive polymer PEDOT:PSS, and a polar auxiliary agent in a preset ratio to obtain a printable electrode ink; print the electrode ink on the flexible liquid crystal elastomer substrate prepared in Step 1 to obtain the interdigitated electrodes.

[0013] Step 3: Uniformly mix an ionic liquid, a thiol - ene photocurable monomer, and a photo - initiator in a preset ratio to obtain an electrolyte ink; uniformly cover the electrolyte ink on the interdigitated electrodes prepared in Step 2, and perform an in - situ photopolymerization reaction using ultraviolet light to obtain the quasi - solid electrolyte layer.

[0014] Step 4: Print silver conductive glue on the back of the liquid crystal elastomer substrate to obtain a heating circuit, and obtain an electro - controllable programmable deformation micro - supercapacitor composed of a quasi - solid electrolyte layer, interdigitated electrodes, a flexible liquid crystal elastomer substrate, and a heating circuit.

[0015] In the above technical solution, the heating circuit is a serpentine heating circuit or a strip heating circuit.

[0016] In the above technical solution, in step 1, the mass ratio of the monofunctional polymerizable liquid crystal monomer, the bifunctional polymerizable liquid crystal monomer, the chain extender, and the photoinitiator is (5.0 - 10.0):(70.0 - 95.0):(15.0 - 30.0):(0.5 - 2.0);

[0017] The monofunctional polymerizable liquid crystal monomer is selected from one or more of the compounds of formula (I) and (II), and the bifunctional polymerizable liquid crystal monomer is selected from one or more of the compounds of formula (III):

[0018]

[0019]

[0020] In formula (I), (II) and (III), X or Y is an aromatic ring or an alicyclic ring. Preferably, when X or Y is an aromatic ring, X or Y is a 1,4 - benzene ring, a 2,5 - pyrimidine ring or a 1,2,6 - naphthalene ring. When X or Y is an alicyclic ring, X or Y is a trans - 1,4 - cyclohexane. When X or Y contains a side group, the side group is a halogen, a cyano group or a methyl group; m and n are each 0 - 4; Z is a phenyl group, an ester group, an alkynyl group, an alkyl group, a nitrogen - nitrogen double bond, an ether bond or a direct connection; R1 or R2 or R3 is an alkyl group containing 1 - 16 carbon atoms, an alkoxy group containing 1 - 16 carbon atoms, a siloxanyl group containing 1 - 16 atoms, an ester group, a cyano group, a halogen, an isothiocyanato group or a nitro group;

[0021] The chain extender is selected from dithiol monomers, including but not limited to one or more of 2,2 - (ethylenedioxy)diethanethiol, 1,3 - propanedithiol, 1,6 - hexanedithiol;

[0022] The photoinitiator is an ultraviolet photoinitiator having an absorption capacity in the range of 250 - 420 nm. Preferably, the photoinitiator is one or more of benzoin dimethyl ether (I - 651), 1 - hydroxycyclohexyl phenyl ketone (I - 184), 2 - hydroxy - 2 - methyl - 1 - phenyl - 1 - propanone (I - 1173), 2 - hydroxy - 4 - (2 - hydroxyethoxy)-2 - methylpropiophenone (I - 2959).

[0023] In the above technical solution, in step 1, the prepared liquid crystal precursor is poured into the printing cartridge, the height of the printing nozzle is adjusted, and programming design of the printing path, printing speed and extrusion air pressure is carried out. After holding at a specific temperature, printing is performed. Preferably, the diameter of the printing nozzle is 0.1 - 0.6 mm; the printing speed is 2 - 12 mm / s; the extrusion air pressure is 0.1 - 0.6 MPa; the specific holding temperature is 15 - 65 °C, and the holding time is 0.5 - 4 h.

[0024] In the above technical solution, in step 1, the light source for the in-situ photopolymerization reaction is a UV light source with a wavelength of 254 - 520 nm, and the light intensity is 5 - 200 mW / cm 2 , and the polymerization time is 60 - 1800 s.

[0025] In the above technical solution, in step 2, the mass ratio of MXene nanosheets, the conductive polymer PEDOT:PSS in the aqueous solution of conductive polymer PEDOT:PSS, and the polar additive is (10.0 - 50.0):(50.0 - 95.0):(0.5 - 2.0);

[0026] The MXene nanosheets include but are not limited to Ti3C2T x , Ti2CT x , Ti4N3T x , Ti3CNT x , Cr2TiC2T x , Mo2CT x , Mo2TiC2T x , Mo2Ti2C3T x , Nb2CT x , V2CT x or one or more of them, and the lateral size of the ultrathin MXene nanosheets is 0.1 - 10 μm;

[0027] The concentration of the aqueous solution of the conductive polymer PEDOT:PSS is 1 - 3 wt.%.

[0028] The polar additives include but are not limited to one or more of dimethyl sulfoxide, dimethylformamide, tetrahydrofuran, ethanol, isopropanol, ethylene glycol, glycerol, concentrated sulfuric acid, hydrochloric acid, phosphoric acid, ionic liquids.

[0029] In the above technical solution, in step 2, the prepared electrode ink is poured into the printing cartridge, the height of the printing nozzle is adjusted, and programming design of the printing path, printing speed and extrusion air pressure is carried out, and then printing is performed. Preferably, the diameter of the printing nozzle is 0.05 - 0.3 mm; the printing speed is 1 - 10 mm / s; the extrusion air pressure is 0.01 - 0.2 MPa.

[0030] In the above technical solution, in step 3, the mass ratio of the ionic liquid, thiol-ene photocurable monomer, and photoinitiator is (65.0 - 90.0):(10.0 - 30.0):(0.5 - 2.0);

[0031] The ionic liquid is selected from imidazole-based ionic liquids. The cationic component is 1-alkylimidazole, 1-alkyl-3-methylimidazole, or 1-alkyl-2,3-dimethylimidazole, where the alkyl group is methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl, decyl, dodecyl, tetradecyl, hexadecyl, or octadecyl; the anionic component is chlorine, bromine, iodine, tetrafluoroborate, hexafluorophosphate, acetate, bis(trifluoromethanesulfonyl)imide, nitrate, perchlorate, hydrogen sulfate, dihydrogen phosphate, trifluoromethanesulfonic acid, trifluoroacetic acid, or p-toluenesulfonic acid;

[0032] The thiol-ene photocurable monomer is trimethylolpropane tris(3-mercaptopropionate) (TMPTMP) and trimethylolpropane triacrylate (TMPTA), and the molar ratio of the two is 1:1 - 1:4;

[0033] The photoinitiator is an ultraviolet photoinitiator having light absorption ability in the range of 250 - 420 nm. Preferably, the photoinitiator is one or more of benzoin dimethyl ether (I-651), 1-hydroxycyclohexyl phenyl ketone (I-184), 2-hydroxy-2-methyl-1-phenyl-1-propanone (I-1173), and 2-hydroxy-4-(2-hydroxyethoxy)-2-methylpropiophenone (I-2959).

[0034] In the above technical solution, in step 3, the prepared electrolyte ink is poured into the printing cartridge, the height of the printing nozzle is adjusted, the printing path, printing speed, and extrusion air pressure are programmed, and then printing is carried out. Preferably, the diameter of the printing nozzle is 0.05 - 0.2 mm; the printing speed is 4 - 10 mm / s; the extrusion air pressure is 0.01 - 0.2 MPa.

[0035] In the above technical solution, in step 3, the light source for the in-situ photopolymerization reaction is a UV light source with a wavelength of 254 - 520 nm, and the light intensity is 5 - 200 mW / cm 2 , and the polymerization time is 60 - 1800 s.

[0036] In the above technical solution, in step 4, the diameter of the nozzle for printing silver conductive paste is 0.05 - 0.3 mm; the printing speed is 1 - 10 mm / s; the extrusion air pressure is 0.01 - 0.2 MPa.

[0037] In the above technical solution, in step 4, after the heating circuit is obtained, it is encapsulated with a polyimide film.

[0038] Another aspect of the present invention also includes the application of the electrically controlled programmable deformable micro-supercapacitor based on liquid crystal elastomer. By applying a certain voltage to the heating circuit to generate an electrothermal effect, under the action of the thermal effect, the flexible liquid crystal elastomer substrate drives the entire micro-supercapacitor to achieve a variety of reversible deformation modes such as bending, twisting, and folding. At the same time, the interdigital electrodes and the quasi-solid electrolyte layer will not be damaged during the deformation process, and stable energy storage performance can be maintained. The interdigital electrodes are used to store electrical energy in the micro-supercapacitor, and good electrochemical performance can be achieved.

[0039] In the above technical solution, the heating circuit is evenly distributed on the back of the entire flexible liquid crystal elastomer substrate. During the heating process, the entire flexible liquid crystal elastomer substrate drives the entire micro supercapacitor to undergo reversible deformation. Alternatively, the heating circuit is arranged at a specific position on the back of the flexible liquid crystal elastomer substrate. During the heating process, the position corresponding to the heating circuit is deformed, thereby driving the local position of the micro supercapacitor to deform. In this way, the deformation of the micro supercapacitor is achieved by controlling the opening and closing of the heating circuit.

[0040] In the above technical solution, the electrically controlled programmable deformable micro supercapacitor based on liquid crystal elastomer is integrated with the infrared sensor, the two ends of the interdigital electrode are electrically connected to the infrared sensor to power it, the infrared sensor is electrically connected to a microcontroller, the microcontroller is communicatively connected to a DC power distributor, and the DC power distributor is electrically connected to the two ends of the heating circuit through an electrical conductor to achieve adaptive grasping.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] 1. The electrically controlled programmable deformable micro-supercapacitor based on liquid crystal elastomer of the present invention cleverly combines the stimulus response performance of liquid crystal elastomer with the excellent electrochemical properties of micro-supercapacitor. Compared with traditional energy storage devices with fixed geometry, the device can perform rapid and reversible response deformation under low voltage stimulation while maintaining high energy density, excellent rate performance and good cycle life.

[0043] 2. The electrically controlled programmable deformable micro-supercapacitor of the liquid crystal elastomer of the present invention can realize various deformation modes including bending, twisting, folding, etc. through reasonable design and regulation of the 3D printed liquid crystal elastomer and the heating circuit, realize deformation control in different time domains and regions, and has high programmability.

[0044] 3. The electrically controlled programmable deformable micro-supercapacitor of the liquid crystal elastomer of the present invention can be further combined with a sensor to realize autonomous recognition of the target object, and has broader application prospects in the fields of soft robots, wearable electronics and intelligent monitoring systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a schematic diagram of the preparation process of an electrically controlled programmable deformable micro-supercapacitor based on 3D-printed liquid crystal elastomer.

[0046] Figure 2 It is a topographic map of the cross-section of an electrically controlled programmable deformable micro-supercapacitor based on 3D-printed liquid crystal elastomer.

[0047] Figure 3 It is the cyclic voltammetry curve of an electrically controlled programmable deformable micro-supercapacitor based on 3D-printed liquid crystal elastomer.

[0048] Figure 4 It is the galvanostatic charge-discharge curve of an electrically controlled programmable deformable micro-supercapacitor based on 3D-printed liquid crystal elastomer.

[0049] Figure 5 It is the bending deformation and corresponding infrared thermal imaging photos of an electrically controlled programmable deformable micro-supercapacitor based on 3D-printed liquid crystal elastomer.

[0050] Figure 6 It is the heating effect diagram (i.e., time-temperature curve) of an electrically controlled programmable deformable micro-supercapacitor based on 3D-printed liquid crystal elastomer at different voltages.

[0051] Figure 7 It is the cyclic voltammetry curves of an electrically controlled programmable deformable micro-supercapacitor based on 3D-printed liquid crystal elastomer at (a) different bending angles and (b) different temperatures.

[0052] Figure 8 It is the schematic diagram and photo of the sequential folding deformation of an electrically controlled programmable deformable micro-supercapacitor based on 3D-printed liquid crystal elastomer.

[0053] Figure 9 It is the schematic diagram and photo of the simultaneous folding deformation of an electrically controlled programmable deformable micro-supercapacitor based on 3D-printed liquid crystal elastomer.

[0054] Figure 10 It is the schematic diagram and photo of the integration of an electrically controlled programmable deformable micro-supercapacitor based on 3D-printed liquid crystal elastomer with an infrared sensor to achieve autonomous grasping.

[0055] Figure 11 It is the voltage and bending angle change diagram (i.e., time-voltage / bending angle curve) during the autonomous grasping process of the integration of an electrically controlled programmable deformable micro-supercapacitor based on 3D-printed liquid crystal elastomer with an infrared sensor. Specific implementation method

[0056] The present invention will be further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0057] Example 1

[0058] A preparation method of an electrically controlled programmable deformable micro-supercapacitor based on 3D printed liquid crystal elastomer, comprising the following steps:

[0059] Step 1, Weigh 698 mg of RM257 and 320 mg of C6BAPE, heat them to complete dissolution of the monomers at 70 °C, then add 290 mg of EDDET, 20 mg of triethylamine (TEA), and 10 mg of I-651. Stir the mixed solution for 2 min to make it uniformly mixed, and then transfer it to the printing cartridge. Select a printing nozzle diameter of 0.15 mm, a printing speed of 10 mm / s, an extrusion air pressure of 0.3 MPa, a printing nozzle height of 0.2 mm from the substrate, keep the printing cartridge at 65 °C for 2 h, and then uniformly extrude the liquid crystal precursor in the horizontal direction. Finally, irradiate it with ultraviolet light of 20 mW / cm 2 for 600 s for curing to obtain a liquid crystal elastomer film.

[0060] Step 2, Add 3.2 g of lithium fluoride (LiF) to 40 mL of 9 mol / L hydrochloric acid (HCl) solution, stir for 10 min, then slowly add 2 g of Ti3AlC2 powder, and react at 50 °C for 36 h. Centrifuge and wash the reaction product with deionized water until pH≥6. Redisperse the precipitate in deionized water, first centrifuge at a speed of 3000 rpm for 15 min, and then centrifuge the collected supernatant at a speed of 9800 rpm for 10 min. The obtained sludge-like precipitate is the synthesized MXene nanosheets (the average lateral size of the nanosheets is 1.5 μm). Uniformly mix 40 mg of MXene nanosheets, 10 mL of PEDOT:PSS aqueous solution (concentration of 1 wt.%), and 50 mg of dimethyl sulfoxide (DMSO), transfer it to the printing cartridge. Select a printing nozzle diameter of 0.1 mm, a printing speed of 10 mm / s, an extrusion air pressure of 0.1 MPa, a printing nozzle height of 0.1 mm from the substrate, and then uniformly print the electrode ink on the liquid crystal elastomer substrate prepared in Step 1 to obtain an interdigitated electrode.

[0061] Step 3: Uniformly mix 338 mg of TMPTMP, 296 mg of TMPTA, 1.58 g of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMIM TFSI), and 10 mg of I-651, and transfer the mixture to a printing cartridge. Select a printing nozzle diameter of 0.2 mm, a printing speed of 6 mm / s, an extrusion air pressure of 0.05 MPa, and a printing nozzle height of 0.1 mm from the substrate. Then, uniformly cover the entire interdigital electrode prepared in Step 2 with the electrolyte ink. Finally, irradiate it with ultraviolet light at 20 mW / cm 2 for 600 s for curing to obtain a quasi-solid-state electrolyte.

[0062] Step 4: Transfer the silver conductive adhesive to a printing cartridge. Select a printing nozzle diameter of 0.1 mm, a printing speed of 2 mm / s, an extrusion air pressure of 0.15 MPa, and a printing nozzle height of 0.1 mm from the substrate. Then, print the silver conductive adhesive on the back of the liquid crystal elastomer substrate to obtain a serpentine heating circuit, and encapsulate it with a polyimide film to obtain an electrically controlled programmable deformation micro-supercapacitor composed of a quasi-solid-state electrolyte, an interdigital electrode, a flexible liquid crystal elastomer substrate, and a serpentine heating circuit, denoted as LCE-MSC. The schematic diagram of the preparation process is as Figure 1 shown.

[0063] The structural formulas of the reactants used in this example are as follows:

[0064]

[0065] Figure 2 is the microstructure of LCE-MSC under SEM. Due to the encapsulation and protection of the interdigital electrode and the heating circuit by the quasi-solid-state electrolyte formed by thiol-ene and the polyimide film respectively, and the charge interaction between the surface of the liquid crystal elastomer after plasma treatment and the electrode ink, it can be seen from the figure that the interdigital electrode and the heating circuit are tightly combined with the liquid crystal elastomer substrate, and no obvious delamination phenomenon or structural defect is found.

[0066] Figure 3 is the cyclic voltammogram of LCE-MSC. It can be seen from the figure that at different scanning rates, the cyclic voltammogram of LCE-MSC shows an almost quasi-rectangular shape, indicating its typical electrochemical behavior. Especially at a scanning rate of 100 mV / cm 2 LCE-MSC shows a satisfactory rectangular shape and has the maximum response current, which reflects its strong charge storage ability and fast electron transfer inside the microelectrode.

[0067] Figure 4The constant current charge-discharge curve of the LCE-MSC is shown. It can be seen from the figure that the constant current charge-discharge curve presents a symmetric triangular shape, further confirming its fast and reversible electrochemical reaction. These values fully demonstrate the excellent capacitive characteristics and good rate performance of the LCE-MSC.

[0068] Figure 5 The bending deformation of the LCE-MSC and the corresponding infrared thermal imaging photos are shown. It can be seen from the figure that when a DC voltage of 2.5 V is applied to the heating circuit, the LCE-MSC can reach a maximum bending angle of about 200° within 40 s, and the maximum temperature of the LCE-MSC at this time is about 50 °C.

[0069] Figure 6 The graph of the temperature change of the LCE-MSC over time observed by infrared thermal imaging at different voltages is shown. It can be seen from the figure that when the DC voltage changes from 1.0 V to 2.0 V, the temperature of the LCE-MSC can be controlled within 60 °C, which minimizes the adverse effects on its electrochemical performance.

[0070] Figure 7 The cyclic voltammetry curves of the LCE-MSC at (a) different bending angles and (b) different temperatures are shown. It can be seen from Figure (a) that the LCE-MSC maintains highly stable electrochemical performance during the bending deformation process. Even when the bending angle reaches 180°, its CV curve hardly changes, showing a high capacity retention rate. It can be seen from Figure (b) that the LCE-MSC exhibits excellent electrochemical stability in the range of 30 °C to 80 °C, demonstrating its electrochemical stability in a high-temperature environment.

[0071] Example 2

[0072] A preparation method of an electro-controlled programmable deformation micro-supercapacitor based on 3D printed liquid crystal elastomer, comprising the following steps:

[0073] Step 1, Weigh 452 mg of RM257 and 376 mg of RM82, heat them to complete dissolution of the monomers at 70 °C, then add 240 mg of 1,6-hexanedithiol, 10 μL of dipropylamine (DPA), and 10 mg of I-651. Stir the mixed solution for 2 min to make it evenly mixed, and then transfer it to the printing cartridge. Select a printing nozzle diameter of 0.3 mm, a printing speed of 8 mm / s, an extrusion air pressure of 0.4 MPa, the height of the printing nozzle from the substrate is 0.2 mm, keep the printing cartridge at 65 °C for 2 h, then evenly extrude the liquid crystal precursor along the horizontal direction, and finally irradiate it with ultraviolet light of 20 mW / cm 2 for 600 s for curing to obtain a liquid crystal elastomer film.

[0074] Step 2: Add 3.2 g of lithium fluoride (LiF) to 40 mL of 9 mol / L hydrochloric acid (HCl) solution, stir for 10 min, then slowly add 2 g of Ti3AlC2 powder, and react at 50 °C for 36 h. Centrifuge and wash the reaction product with deionized water until pH ≥ 6. Redisperse the precipitate in deionized water, centrifuge at 3000 rpm for 15 min first, and then centrifuge the collected supernatant at 9800 rpm for 10 min. The resulting sludge-like precipitate is the synthesized MXene nanosheets (the average lateral size of the nanosheets is 1.5 μm). Uniformly mix 50 mg of MXene nanosheets, 10 mL of PEDOT:PSS aqueous solution (concentration of 1 wt.%), and 50 mg of ethylene glycol (EG), and transfer them to a printing cartridge. Select a printing nozzle diameter of 0.1 mm, a printing speed of 6 mm / s, an extrusion air pressure of 0.05 MPa, and a printing nozzle height 0.1 mm from the substrate. Then uniformly print the electrode ink on the liquid crystal elastomer substrate prepared in Step 1 to obtain an interdigital electrode.

[0075] Step 3: Uniformly mix 427 mg of TMPTMP, 309 mg of TMPTA, 2.06 g of 1-ethyl-3-methylimidazolium chloride (EMIMCl), and 10 mg of I-651, and transfer them to a printing cartridge. Select a printing nozzle diameter of 0.1 mm, a printing speed of 8 mm / s, an extrusion air pressure of 0.02 MPa, and a printing nozzle height 0.1 mm from the substrate. Then uniformly cover the entire interdigital electrode prepared in Step 2 with the electrolyte ink, and finally irradiate it with ultraviolet light at 20 mW / cm 2 for 600 s for curing to obtain a quasi-solid electrolyte.

[0076] Step 4: Transfer the silver conductive adhesive to a printing cartridge. Select a printing nozzle diameter of 0.1 mm, a printing speed of 3 mm / s, an extrusion air pressure of 0.1 MPa, and a printing nozzle height 0.1 mm from the substrate. Then use the silver conductive adhesive to print thin strip heating circuits on the back of each interval of the interdigital electrode, connect wires to both ends of each heating circuit respectively to achieve independent control of each heating circuit, and finally encapsulate it with a polyimide film to obtain an LCE-MSC that can achieve autonomous folding and deformation.

[0077] The structural formulas of the reactants used in this example are as follows:

[0078]

[0079] Figure 8Schematic diagram and photo of the sequential folding deformation of the LCE-MSC with a thin strip-shaped heating circuit. As can be seen from the figure, the entire LCE-MSC is divided into three regions, with a set of interdigital electrodes arranged in each region, and a heating circuit is arranged between every two adjacent regions, for a total of two heating circuits. Now, a DC voltage is applied to one of the heating circuits, and then a DC voltage is applied to the other heating circuit. The LCE-MSC with a thin strip-shaped heating circuit will fold sequentially like an accordion, vertically stacking the originally flat capacitor units within a limited area, thereby forming a more compact structure with a smaller size to achieve high areal density energy storage.

[0080] Figure 9 Schematic diagram and photo of the simultaneous folding deformation of the LCE-MSC with a thin strip-shaped heating circuit. The entire LCE-MSC is divided into five regions, with a set of interdigital electrodes arranged in each region. The middle region is a square region, and each edge of the middle region is connected to an outer region. A heating circuit is provided at each position where the middle region is connected to the outer region. As can be seen from the figure, relying on its self-folding ability, the LCE-MSC directly deforms from a two-dimensional strip to a three-dimensional structure. When a DC voltage is applied to all the thin strip-shaped heating circuits, the LCE-MSC will fold simultaneously to form a cuboid structure; when the power is turned off and the temperature of the LCE-MSC cools to room temperature, it can immediately return to the initial flat state.

[0081] Example 3

[0082] A preparation method of an electro-controlled programmable deformation micro-supercapacitor based on 3D printed liquid crystal elastomer, comprising the following steps:

[0083] Step 1, weigh 1.35 g of RM257 and 0.82 g of RM82, heat them to 70 °C until the monomers are completely dissolved, then add 500 mg of EDDET, 50 mg of tetraallyloxyethane (GDA), 50 mg of triethylamine (TEA) and 20 mg of I-651. Stir the mixed solution for 2 min to make it evenly mixed, and then transfer it to the printing cartridge. Select a printing nozzle diameter of 0.4 mm, a printing speed of 5 mm / s, an extrusion air pressure of 0.5 MPa, a printing nozzle height 0.2 mm from the substrate, keep the printing cartridge at 65 °C for 2 h, then extrude the liquid crystal precursor evenly in the horizontal direction, and finally irradiate it with ultraviolet light of 20 mW / cm 2 for 600 s for curing to obtain a liquid crystal elastomer film.

[0084] Step 2: Add 3.2 g of lithium fluoride (LiF) to 40 mL of 9 mol / L hydrochloric acid (HCl) solution, stir for 10 min, then slowly add 2 g of Ti3AlC2 powder, and react at 50 °C for 36 h. Centrifuge and wash the reaction product with deionized water until the pH ≥ 6. Redisperse the precipitate in deionized water, centrifuge at 3000 rpm for 15 min first, and then centrifuge the collected supernatant at 9800 rpm for 10 min. The resulting sludge-like precipitate is the synthesized MXene nanosheets (the average lateral size of the nanosheets is 1.5 μm). Uniformly mix 50 mg of MXene nanosheets, 10 mL of PEDOT:PSS aqueous solution (concentration of 1 wt.%), and 15 mg of 1-ethyl-3-methylimidazolium tricyanomethanide (EMIM TCM), and transfer them to the printing cartridge. Select a printing nozzle diameter of 0.05 mm, a printing speed of 6 mm / s, an extrusion air pressure of 0.08 MPa, and a printing nozzle height of 0.1 mm from the substrate. Subsequently, uniformly print the electrode ink on the liquid crystal elastomer substrate prepared in Step 1 to obtain an interdigital electrode.

[0085] Step 3: Uniformly mix 467 mg of TMPTMP, 364 mg of TMPTA, 2.25 g of 1-ethyl-3-methylimidazolinium bis(trifluoromethylsulfonyl)imide (EMIM TFSI), and 15 mg of I-651, and transfer them to the printing cartridge. Select a printing nozzle diameter of 0.1 mm, a printing speed of 8 mm / s, an extrusion air pressure of 0.05 MPa, and a printing nozzle height of 0.1 mm from the substrate. Subsequently, uniformly cover the entire interdigital electrode prepared in Step 2 with the electrolyte ink, and finally irradiate it with ultraviolet light of 20 mW / cm 2 for 600 s for curing to obtain a quasi-solid electrolyte.

[0086] Step 4: Transfer the silver conductive adhesive to the printing cartridge. Select a printing nozzle diameter of 0.05 mm, a printing speed of 2 mm / s, an extrusion air pressure of 0.15 MPa, and a printing nozzle height of 0.1 mm from the substrate. Subsequently, print the silver conductive adhesive on the back of the liquid crystal elastomer substrate to obtain a serpentine heating circuit, and encapsulate it with a polyimide film to obtain an LCE-MSC composed of a quasi-solid electrolyte, an interdigital electrode, a flexible liquid crystal elastomer substrate, and a serpentine heating circuit.

[0087] Step 5: Connect the two ends of the interdigital electrode on the LCE-MSC to the infrared sensor with copper wires. The infrared sensor is externally connected to a microcontroller and a DC power distributor, and the DC power distributor is electrically connected to the two ends of the serpentine heating circuit on the LCE-MSC with copper wires to obtain an electronic device that can autonomously identify foreign objects and grasp them.

[0088] The structural formulas of the reactants used in this embodiment are as follows:

[0089]

[0090] Figure 10 It is a schematic diagram and photo of the integration of LCE-MSC and an infrared sensor to achieve the autonomous grasping function. As can be seen from the figure, four series-connected LCE-MSCs supply power to the infrared sensor. The infrared sensor includes an infrared transmitter and a receiver. The transmitter projects a light signal, and then the reflected light is received to sense the presence of an object according to its intensity. The microcontroller reads the signal changes of the infrared sensor in real time, and the DC power distributor independently regulates the current of the four heating circuits. When the green sphere moves within 2 cm above the sensor, the signal of the infrared sensor changes, and the microcontroller reads the signal change, and then controls the DC power distributor to provide a DC voltage for the heating circuit. The LCE-MSC rapidly deforms under electrothermal drive, and finally completes the precise grasping of the target sphere.

[0091] Figure 11 It is the relationship between the bending angle of each LCE-MSC and the average input / output voltage with time during the movement of the object. As can be seen from the figure, when the green sphere approaches the infrared sensor, the output voltage instantaneously jumps from 0 V to 2 V, and the LCE-MSC completes a bending deformation of up to 180° within 33 s, demonstrating the function of autonomously identifying and grasping foreign objects.

[0092] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. An electro-controlled programmable deformable micro-supercapacitor based on liquid crystal elastomer, characterized in that, It sequentially includes a flexible liquid crystal elastomer substrate, interdigital electrodes, and a quasi-solid electrolyte layer from bottom to top, and a heating circuit is provided at the bottom of the flexible liquid crystal elastomer substrate.

2. The electronically controllable programmable deformable micro-supercapacitor according to claim 1, wherein The electrically controlled programmable deformable micro-supercapacitor is encapsulated by a polyimide film.

3. The preparation method of the electronically controlled programmable deformable micro-supercapacitor according to claim 1, characterized in that, It includes the following steps: Step 1, uniformly mix a monofunctional polymerizable liquid crystal monomer, a bifunctional polymerizable liquid crystal monomer, a chain extender, and a photoinitiator in a preset ratio to prepare a polymerizable liquid crystal precursor; print the liquid crystal precursor onto a preselected substrate by a printing method; finally, perform an in-situ photopolymerization reaction using ultraviolet light, and then the liquid crystal elastomer can be peeled off from the substrate to obtain the flexible liquid crystal elastomer substrate; Step 2, uniformly mix MXene nanosheets, a conductive polymer PEDOT:PSS aqueous solution, and a polar auxiliary agent in a preset ratio to prepare a printable electrode ink; print the electrode ink on the flexible liquid crystal elastomer substrate prepared in Step 1 to obtain the interdigital electrodes; Step 3, uniformly mix an ionic liquid, a thiol-ene photocurable monomer, and a photoinitiator in a preset ratio to prepare an electrolyte ink; uniformly cover the electrolyte ink on the interdigital electrodes prepared in Step 2 by a printing method, and perform an in-situ photopolymerization reaction using ultraviolet light to obtain the quasi-solid electrolyte layer; Step 4, print silver conductive paste on the back of the liquid crystal elastomer substrate to obtain a heating circuit, and obtain an electrically controlled programmable deformable micro-supercapacitor composed of a quasi-solid electrolyte layer, interdigital electrodes, a flexible liquid crystal elastomer substrate, and a heating circuit. Preferably, the heating circuit is a serpentine heating circuit or a strip heating circuit.

4. The preparation method of the electrically controlled programmable deformable micro-supercapacitor according to claim 3, characterized in that, In Step 1, the mass ratio of the monofunctional polymerizable liquid crystal monomer, the bifunctional polymerizable liquid crystal monomer, the chain extender, and the photoinitiator is (5.0 - 10.0):(70.0 - 95.0):(15.0 - 30.0):(0.5 - 2.0); The monofunctional polymerizable liquid crystal monomer is selected from one or more of the compounds of formula (I) and (II), and the bifunctional polymerizable liquid crystal monomer is selected from one or more of the compounds of formula (III): In formula (I), (II), and (III), X or Y is an aromatic ring or an alicyclic ring. Preferably, when X or Y is an aromatic ring, X or Y is a 1,4-benzenoid ring, a 2,5-pyrimidine ring, or a 1,2,6-naphthalene ring; when X or Y is an alicyclic ring, X or Y is a trans-1,4-cyclohexane. When X or Y contains a side group, the side group is a halogen, a cyano group, or a methyl group; m and n are respectively 0 - 4; Z is a phenyl group, an ester group, an alkynyl group, an alkyl group, a nitrogen-nitrogen double bond, an ether bond, or a direct connection; R1 or R2 or R3 is an alkyl group containing 1 - 16 carbon atoms, an alkoxy group containing 1 - 16 carbon atoms, a siloxanyl group containing 1 - 16 atoms, an ester group, a cyano group, a halogen, an isothiocyanato group, or a nitro group; The chain extender is selected from dithiol monomers, including but not limited to one or more of 2,2-(ethylenedioxy)diethanethiol, 1,3-propanedithiol, and 1,6-hexanedithiol; The photoinitiator is an ultraviolet photoinitiator having light absorption ability in the range of 250-420 nm. Preferably, the photoinitiator is one or more of benzoin dimethyl ether (I-651), 1-hydroxycyclohexyl phenyl ketone (I-184), 2-hydroxy-2-methyl-1-phenyl-1-propanone (I-1173), and 2-hydroxy-4-(2-hydroxyethoxy)-2-methylpropiophenone (I-2959). Preferably, in step 1, the prepared liquid crystal precursor is poured into the printing cartridge, the height of the printing nozzle is adjusted, and programming design of the printing path, printing rate, and extrusion air pressure is carried out. After heat preservation at a specific temperature, printing is performed. Preferably, the diameter of the printing nozzle is 0.1-0.6 mm; the printing rate is 2-12 mm / s; the extrusion air pressure is 0.1-0.6 MPa; the specific heat preservation temperature is 15-65 °C, and the heat preservation time is 0.5-4 h. Preferably, in the step 1, the light source for the in-situ photopolymerization reaction is a UV light source with a wavelength of 254-520 nm, the light intensity is 5-200 mW / cm 2 , and the polymerization time is 60-1800 s.

5. The preparation method of the electronically controlled programmable deformable micro-supercapacitor according to claim 3, characterized in that, In step 2, the mass ratio of MXene nanosheets, the conductive polymer PEDOT:PSS in the aqueous solution of conductive polymer PEDOT:PSS, and the polar auxiliary is (10.0-50.0):(50.0-95.0):(0.5-2.0); The MXene nanosheets include but are not limited to Ti3C2T x , Ti2CT x , Ti4N3T x , Ti3CNT x , Cr2TiC2T x , Mo2CT x , Mo2TiC2T x , Mo2Ti2C3T x , Nb2CT x , V2CT x or more than one of them, and the lateral size of the ultrathin MXene nanosheets is 0.1 - 10 μm; the concentration of the aqueous solution of the conductive polymer PEDOT:PSS is 1-3 wt.%; the polar auxiliary includes, but is not limited to, one or more of dimethyl sulfoxide, dimethylformamide, tetrahydrofuran, ethanol, isopropanol, ethylene glycol, glycerol, concentrated sulfuric acid, hydrochloric acid, phosphoric acid, and ionic liquid. Preferably, in step 2, the prepared electrode ink is poured into the printing cartridge, the height of the printing nozzle is adjusted, and programming design of the printing path, printing rate, and extrusion air pressure is carried out, and then printing is performed. Preferably, the diameter of the printing nozzle is 0.05-0.3 mm; the printing rate is 1-10 mm / s; the extrusion air pressure is 0.01-0.2 MPa.

6. The preparation method of the electrically controlled programmable deformable micro-supercapacitor according to claim 3, characterized in that, In step 3, the mass ratio of the ionic liquid, the thiol-ene photocurable monomer, and the photoinitiator is (65.0-90.0):(10.0-30.0):(0.5-2.0); the ionic liquid is selected from imidazole-based ionic liquids, and the cationic composition is 1-alkylimidazole, 1-alkyl-3-methylimidazole, or 1-alkyl-2,3-dimethylimidazole, where the alkyl is methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl, decyl, dodecyl, tetradecyl, hexadecyl, or octadecyl; the anionic composition is chlorine, bromine, iodine, tetrafluoroboric acid, hexafluorophosphoric acid, acetic acid, bis(trifluoromethanesulfonyl)imide, nitric acid, perchloric acid, hydrogen sulfate, dihydrogen phosphate, trifluoromethanesulfonic acid, trifluoroacetic acid, or p-toluenesulfonic acid; the thiol-ene photocurable monomer is trimethylolpropane tris(3-mercaptopropionate) (TMPTMP) and trimethylolpropane triacrylate (TMPTA), and the molar ratio of the two is 1:1-1:4; The photoinitiator is an ultraviolet photoinitiator having light absorption ability in the range of 250 to 420 nm. Preferably, the photoinitiator is one or more of benzoin dimethyl ether (I-651), 1-hydroxycyclohexyl phenyl ketone (I-184), 2-hydroxy-2-methyl-1-phenyl-1-propanone (I-1173), and 2-hydroxy-4-(2-hydroxyethoxy)-2-methylpropiophenone (I-2959). Preferably, in step 3, the prepared electrolyte ink is poured into the printing cartridge, the height of the printing nozzle is adjusted, the printing path, printing speed, and extrusion air pressure are programmed, and then printing is performed. Preferably, the diameter of the printing nozzle is 0.05 to 0.2 mm; the printing speed is 4 to 10 mm / s; The extrusion air pressure is 0.01 to 0.2 MPa. Preferably, in the step 3, the light source for the in-situ photopolymerization reaction is a UV light source with a wavelength of 254-520 nm and a light intensity of 5-200 mW / cm 2 , and the polymerization time is 60-1800 s.

7. The preparation method of the electrically controlled programmable deformable micro-supercapacitor according to claim 3, wherein In step 4, the diameter of the nozzle for printing silver conductive paste is 0.05 to 0.3 mm; the printing speed is 1 to 10 mm / s; the extrusion air pressure is 0.01 to 0.2 MPa. Preferably, after the heating circuit is obtained, it is encapsulated with a polyimide film.

8. The application of the electrically controlled programmable deformable micro-supercapacitor according to claim 1.

9. The application according to claim 8, characterized in that, The heating circuit is uniformly distributed on the back of the entire flexible liquid crystal elastomer substrate, or the heating circuit is arranged at a specific position on the back of the flexible liquid crystal elastomer substrate, and the deformation of the micro-supercapacitor is realized by controlling the on-off of the heating circuit.

10. The application according to claim 8, characterized in that, The electrically controlled programmable deformable micro-supercapacitor based on liquid crystal elastomer is integrated with an infrared sensor. Both ends of the interdigital electrode are electrically connected to the infrared sensor to supply power to it. The infrared sensor is electrically connected to a microcontroller, and the microcontroller is communicatively connected to a DC power distributor. The DC power distributor is electrically connected to both ends of the heating circuit through electric wires to achieve adaptive grasping.

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